Mercury seal.



I W. PEARSON.

MERCURY SEAL.

APPLICATION HLED MAY14.1914.

Patented Jan. 11, 1916.

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WALTER PEAR-SDN, 0F WHITMAN, lVlASSACHUSETTS.

MERCURY SEAL.

Specicaton of Letters Patent.

Patented J an. 11, 1916.

Application filed May 14, 1914. Serial No. 838,612.

To all whom t may concern Be it known that 1, WALTER PnAnsoN, a citizen of the United States, and resident of vVhitmam county of Plymouth, State of Massachusetts, have invented an lmprove` ment in Mercury Seals, of which the following description, in connection with the accompanying drawings, is a specification, like letters on` the drawings representing like parts.

My present invention is for a steam tight joint, wherein both supply and return steam pipes convey steam under pressure from a stationary supply to a` revolving part, and back to the stationary part.

It will be readily appreciated that where a circulation of steam is required, both supply and return pipes are necessary. This is especially the case in such machines as a steam heated McKay sewing machine, wherein the shoe horn is rotated and manipulated .during the sewing ot the shoe, which horn must be heated to melt waX and supply the same during such rotation. Heretofore it has been customary to use a gas heated horn, such supply of gas being transferred from a iiXed pipe-in the base of the spindle supporting the base of the horn through an ordinary water seal to a single supply pipe carried on the rotating portion ot the horn, but in this case no supply and return is requisite, and a gas flame is very dangerous and unsatisfactory in such work; To obviate the danger and diiiiculties incin dent.l to gas heating, it has been necessary, heretofore, to provide some sort of a steam tight joint by means of packing. which necessitated such packing being `applied between the iXed and rotating portions, in order to afford a steam tight joint andthis created great friction, interfered with the free manipulation of the rotation of the horn, rendered the sewing of the shoe much more tedious, laborious and diiricult.

My present invention of a steam tight` joint, particularly intended for a McKay type of sewingmachine. but useful in any similar mechanical devices, consists in a mercury seal. a suiiicient volume of mercury being provided to give proper weight and strength to withstand the steam pressure, and furthermore to so arrange the same that. a constant circulation of steam through supply and return pipesis maintained in the lined, as wellasthenrotating, part. o t .the mechanism...

@ther features of the invention, novel combinations of parts, and details of construction, will `be hereinafter more fully pointed out and claimed.

l have illustrated the invention applied to a McKay type of sewing machine, Figure 1 being a fragmentary side view oi' the standard and rotatable horn oiI such a machine; Fig. 2 is an enlarged view, partly in cross section, of the steam tight joint and mercury seal as applied to aV McKay sewing machine: and Fig. 8 is an enlarged cross sectional view on the line 3MB of Fig. 2.

In the drawings, the standard or frame of a Mclav sewing machine of well known type is indicated in general outline at 1, wherein a sewing machine horn 2 mounted on a rotatable platform 3 is carried by a .suitable spindle 4, mounted in bearings 5 in the cross frame 6 of the machine trame l. The further details of a rotatable mechanism are of a commercial type, and are not herein further illustrated, being well known in the art, illustrated, for example, in the Stanley Patent 581,440. A central sleeve 7, which is of appropriate diameter to lit within the spindle 4 and act as a guide therefor is rigidly carried by a bearing 8, attached to the lower cross frame 9. rlhe spindle 4 whichis adapted lto rotate with the horn 2 and platform 3 also carries a cylindrical member 10, which may be formed integrally therewith, or secured thereto by an annular plug 11, intermediate the ends of the members 4 and 10, substantially in position as shown in Fig. 2. To the lower portion or" this plug 11 and between the lowermost extensions of the circular members 4 and 10 is affixed an intermediate partition 12, dividing the annular space below the plug 11 and between the outer diameter of the spindle 4 and the inner diameter of the cylindrical member 10 into two annular channels 13 and 14. The fixed bearing 8 is bored horizontally, on diametrically opposite points to provide partial passages 15 and 16 respectively, to receive a supply pipe 17 and a return pipe 1S. lntercepting the passage 15 and the passage 16 are vertically bored recesses, to receive the short, upstanding pipes 19 and 20 respectively, these pipes being in position to t within theadjacent annular channels 13 and 14. The supply pipe 19 is shown as extending within the channelul, wliile the,return pipe ldextnds upwardly into the annular channel 14. In the plug 11 are bored two horizontal recesses 21 and 22, vertical borings 23 and 211 intercepting the recess 21 in such position that the vertical bore 23 provides communication from the outer cylindrical channel 13, and the boring 21 receives the supply steam pipe 25. It will be appreciated that the plug 11, supply pipe 25, and sleeves al. and 10 are on the rotating part of the horn, while the fixed pipes 17 and 19 on one side, and 18 and 20 on the other, are in the stationary portion of the mechanism, being car ried by the fixed bearing 8. Intercepting the recess 22 is a vertical bored passage 26 from the inner channel 14:, and a second vertical boring 27 carrying the return steam pipe 28.

Incircling the circular member 10 and the parts linst described, is a cylindrical member 29 rigidly secured to the bearing 8 in any suitable manner` and extending upwardly with the flanged top portion 30 to constitute a reservoir or space at the Lipper end thereof, and permitting a small passageway or annular channel 31 between the outer surface of the cylindrical member 10, and the inner surface of said inclosing member 29. This small space or channel 31 extends downwardly, opening into the bottom of the channels 13 and 14:, as clearly shown in Fig. 2. the lower portions of the sleeve 4, cylindrical member 10, and partition 12 being preferably just clear of the top of the fixed bearing 8. iVhen assembled as above described, I pour a suitable amount of mercury into the receptacle 30, which at once flows down the annular passage 31 and fills up the channels 13 and 14 to a suitable height, preferably just below the upper ends of the fixed passages 19 and 20, and substantially to the level as indicated at 32 in Fig. 2. Steam being supplied to the pipe 17 will enter the passage 15 in the fixed bearing S, and fiow upwardly through the pipe 19 above the level of the mercury therein. and fill the annular space 13 between the top of the mercury and the bottom of the plug 11. finally finding an outlet through the vertical passage 23 at any point around this annular space 13. and thence through the bore 21 and 241 into the steam supply pipe 25 on the rotatingportion of the mechanism. The steam being conducted to a suitable heater carried on the platform 3 (not shown) is then returned downwardly through the return pipe 28 to the plug 11 where it finds its way through the bore 22 and passage 26 into the annular space 14, where it also fills this annular space between the top level ofthe mercury 32 and the plug 11 until it finds its way out of the pipe 20, recess 1G, and return pipe 1S in the fixed bearing S.

By utilizing mercury, I am enabled to' provide a steam tight joint between a fixed supply and return, and a rotating supply and return steam heating system, which practically eliminates friction, enables the rotating horn to he manipulated entirely without the necessity of a binding steam tight packing, and with as perfect freedom as in a gas heated device having awater seal. The mercury seal being of greater weight, is sutlicient to'resist a high degree of steam pressure. On the contrary water would be blown out of the passage 31 entirely, or would, of course, tend to condense the steam and be ineffectual. In case of unusual steam pressure, the level 32 of the mercury is lowered in the channels 13 and 14 and forced upwardly in the small annular passage 31, the top flanged reservoir 30 being of sufiicient capacity to hold the entire supply of mercury and prevent its loss should the steam pressure be excessive and force the same upwardly to such a height.

The important feature of enabling a supply and return of gaseous fiuid under pressure by providing a steam tight mercury seal, is believed to be a distinct noveltv, and I wish to claim the same broadly. The arrangement of the circular channels 13 and 111- and plug 11 with the recesses therein to conduct the supply and the return to the proper and appropriate lower channel. is of great importance, affording a full and economical construction, with a steam tight joint, and so arranged as to use a minimum of mercury.

It will be understood that mv invention is not limited to use on a McKay sewing machine, but is of importance in conveying a supply and return through a liquid joint from a fixed to a moving or rotating mechanism. It will also beunderstood that my invention of a mercury seal may be employed to handle gas under pressure. in a practicable and satisfactory manner, either with or without the circulation and return pipe; mercury having the peculiar quality of resisting pressure to a high degree over other liquids, owing to its weight.

Having described my invention. what I claim as new and desire to secure by Letters Patent is:

1. In a device of the kind described. the combination of a rotatable sewing machine spindle and a support therefor, supply and return steam pipes carried by said spindle, a fixed receptacle surrounding said spindle and the steam pipes carried thereby. and containing a quantity of mercury suliicient in weight to withstand normal steam pressure to be supplied. fixed supply and return steam pipes carried by the spindle support and extending through said mercury receptacle above the normal level of the mercury, means permitting said mercury to flow upwardly outside of the rotatable spindle inember and to a considerable height to increase its resistance against excessive steam pressure, and means on said spindle to receive steam from the ixed supply pipe and the rotatable supply pipe and to transfer steam from the rotatable return supply pipe to the fixed supply pipe during rotation of said spindle, whereby a continuous steam circulation is effected.

2. In a device of the kind described, the combination of a rotatable sewing machine spindle and a support therefor, supply and return steam pipes carried by said spindle, a lixed receptacle surrounding said spindle and the steam pipes carried thereby, and containing a quantity of mercury sufficient in weight to withstand normal steam pressure to be supplied, fixed supplv and return steam pipes carried by the spindle support and extending through said mercury receptacle above the normal level of the mercury, means permitting said mercury to flow upwardly outside of the rotatable spindle member and to a considerable height to increase its resistance against excessive steam pressure, and means on said spindle to receive steam from the fixed supply pipe and the rotatable supply pipe and to transfer steam from the rotatable return supply pipe to the ixed supply pipe during rotation of said spindle, said last mentioned means consisting in a partition on the rotatable spindle, bored passages in said spindle connecting the rotatable supply pipe with an annular channel inclosing the fixed return pipe, both said annular channels being immersed in the mercury, whereby continuous steam circulation is eiected.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

WALTER PEAR-SON.

Witnesses:

JAMES R. HODDER, R. J. HERsEY.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

